Adsorption of sodium cyclododecylmethanoate and cycloundecylmethanoate at the air/water interface

1984 ◽  
Vol 62 (11) ◽  
pp. 2359-2363 ◽  
Author(s):  
Jan J. Spitzer
Keyword(s):  
Aqueous Solutions ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Ionic Surfactants ◽  
Free Energies ◽  
Straight Chain ◽  
Double Chain ◽  
Adsorbed State ◽  
Critical Micelle Concentrations ◽  
Air Water Interface

Surface tension measurements on aqueous solutions of sodium cyclododecylmethanoate and sodium cycloundecylmethanoate in sodium carbonate/bicarbonate buffers and at constant sodium ion concentration at 25 °C were used to obtain the standard free energies of adsorption, the saturation areas per surfactant ion, and the critical "micelle" concentrations of these compounds. Similar measurements were done for solutions of sodium dodecanoate for comparisons.The standard free energies of adsorption of CH2 group that is located in a macrocyclic cycloalkyl ring appears to follow the "rule of two" (−RT ln 2) that is also valid for straight chain ionic surfactants. The saturation areas of both cyclododecylmethanoate and cycloundecylmethanoate are about 52 Å2/ion as compared to about 32 Å2/ion for normal dodecanoate.For large ring cycloalkylmethanoates the critical "micelle" concentrations appear to decrease by a factor of about 4/5 for each CH2 group added to the ring as compared to the factor of about 1/2 for each CH2 group added to the chain of normal alkanoates. The data suggest that large cycloalkyl rings have "collapsed ring", or "double chain", conformation in aqueous solutions and in the adsorbed state.

Adsorption of cycloalkane and cyclopentanealkyl acids at the air/water interface

1983 ◽  
Vol 61 (6) ◽  
pp. 1067-1070 ◽  
Author(s):  
Jan J. Spitzer ◽  
Louis D. Heerze
Keyword(s):  
Least Squares ◽  
Carboxylic Acids ◽  
Standard Free Energy ◽  
Nonlinear Least Squares ◽  
Free Energies ◽  
Straight Chain ◽  
Solution Interface ◽  
A Value ◽  
Air Water Interface ◽  
Volume Method

Surface tensions of aqueous solutions of cyclopropane, cyclobutane, cyclopentane, and cycloheptane carboxylic acids, and of cyclopentaneacetic and cyclopentanepropionic acids were measured at 25 °C by the drop volume method. The Traube constants for calculation of standard free energies of adsorption were estimated from second and third degree polynomial least-squares analyses, from nonlinear least-squares analysis using the Szyszkowsky equation, and graphically.The standard free energies of adsorption at the air/solution interface of cycloalkane and cycloalkanealkyl carboxylic acids are less negative than those of the corresponding straight chain acids, but not by a constant amount; the standard free energy of the CH2 group in a cycloalkane ring is −2.5 kJ mol−1 as compared to a value of −3.3 kJ mol−1 for straight chain acids.

Predicting the Critical Micelle Concentrations of Aqueous Solutions of Ionic Liquids and Other Ionic Surfactants

2009 ◽  
Vol 15 (35) ◽  
pp. 8880-8885 ◽  
Author(s):  
U. Preiss ◽  
C. Jungnickel ◽  
J. Thöming ◽  
Ingo Krossing ◽  
J. Łuczak ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Ionic Surfactants ◽  
Critical Micelle Concentrations

Residual phase lignin in haft cooking related to the conditions in the cook

1997 ◽  
Vol 12 (4) ◽  
pp. 225-229
Author(s):  
Cart-in A-S. Gustavsson ◽  
Chritofer T. Lindgren ◽  
Mikael E. Lindström
Keyword(s):  
Hydrogen Sulfide ◽  
Ionic Strength ◽  
Sodium Ion ◽  
Ion Concentration ◽  
Constant Composition ◽  
Hydroxide Ion ◽  
Sulfide Ion ◽  
Residual Phase ◽  
Kraft Cooking ◽  
Very High

Abstract The amount of lignin reacting according to the slow residual phase, i.e. the residual phase lignin, is in many perspectives an interesting issue. The purpose of the present investigation was to develop a mathematical model to show how the amount of residual phase lignin in the kraft cooking of spruce chips (Picm ahies) depends on the conditions in the earlier phases of the cook. The variables studied were hydroxide ion concentration, hydrogen sulfide ion concentration and ionic strength. The liquor-to-wood ratio during pulping was very high to maintain approximately constant chemical concentrations throughout each experiment (so called "constant composition" cooks). An increase in hydroxide ion concentration andtor hydrogen sulfide ion concentration leads to a decrease in the amount of residual phase lignin, while an increase in ionic strength, i.e. sodium ion concentration, leads to an increase. A signiticant result is that the hydrogen sulfide ion concentration has a pronounced influence on the amount of residual phase lignin during a cook at a low hydroxide ion concentration. The amount of residual phase lignin expressed as % lignin on wood, L,, can be described by the following equation developed for "constant composition" cooks (when cooking with a constant sodium ion concentration of 2 mol/L): LT=0,55-0.32*[HO-](-1,3)*ln[HS-] This equation is valid for a concentration of HO- in the range from 0.17 to 1.4, and a hydrogen sulfide ion concentration from 0.07 to 0.6 mol/L.

scholarly journals ALKALOSIS VERSUS ABNORMAL SODIUM ION CONCENTRATION AS A CAUSE OF TETANY

1923 ◽  
Vol 57 (1) ◽  
pp. 47-63
Author(s):  
W. Denis ◽  
L. von Meysenbug ◽  
Julia Goddard
Keyword(s):  
Sodium Ion ◽  
Ion Concentration

scholarly journals Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Chemical Compositions ◽  
Ion Adsorption ◽  
X Ray ◽  
Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

Nucleation of single and mixed straight chain surfactants from dilute aqueous solutions

1996 ◽  
Vol 166 (1-4) ◽  
pp. 189-194 ◽  
Author(s):  
R.N.M.R. van Gelder ◽  
K.J. Roberts ◽  
J. Chambers ◽  
T. Instone
Keyword(s):  
Aqueous Solutions ◽  
Straight Chain ◽  
Dilute Aqueous Solutions
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